diff --git a/gio/gapplicationcommandline.c b/gio/gapplicationcommandline.c
index b3a6d00b4..dcd3301d9 100644
--- a/gio/gapplicationcommandline.c
+++ b/gio/gapplicationcommandline.c
@@ -666,8 +666,8 @@ const gchar *
 g_application_command_line_getenv (GApplicationCommandLine *cmdline,
                                    const gchar             *name)
 {
-  gint length = strlen (name);
-  gint i;
+  size_t length = strlen (name);
+  size_t i;
 
   /* TODO: expand on windows */
   if (cmdline->priv->environ)
diff --git a/gio/gdbus-tool.c b/gio/gdbus-tool.c
index 63c7ec9dc..53e22ebdd 100644
--- a/gio/gdbus-tool.c
+++ b/gio/gdbus-tool.c
@@ -1373,7 +1373,7 @@ dump_method (const GDBusMethodInfo *o,
 {
   guint n;
   guint m;
-  guint name_len;
+  size_t name_len;
   guint total_num_args;
 
   for (n = 0; o->annotations != NULL && o->annotations[n] != NULL; n++)
diff --git a/gio/gdbusconnection.c b/gio/gdbusconnection.c
index 1b31f4b67..2e170a4e2 100644
--- a/gio/gdbusconnection.c
+++ b/gio/gdbusconnection.c
@@ -3822,8 +3822,8 @@ static gboolean
 namespace_rule_matches (const gchar *namespace,
                         const gchar *name)
 {
-  gint len_namespace;
-  gint len_name;
+  size_t len_namespace;
+  size_t len_name;
 
   len_namespace = strlen (namespace);
   len_name = strlen (name);
@@ -3841,7 +3841,7 @@ static gboolean
 path_rule_matches (const gchar *path_a,
                    const gchar *path_b)
 {
-  gint len_a, len_b;
+  size_t len_a, len_b;
 
   len_a = strlen (path_a);
   len_b = strlen (path_b);
diff --git a/gio/gdbusdaemon.c b/gio/gdbusdaemon.c
index 3474b7091..8ad85b9d7 100644
--- a/gio/gdbusdaemon.c
+++ b/gio/gdbusdaemon.c
@@ -543,7 +543,8 @@ match_matches (GDBusDaemon *daemon,
 {
   MatchElement *element;
   Name *name;
-  int i, len, len2;
+  int i;
+  size_t len, len2;
   const char *value;
   int check_type;
 
diff --git a/gio/gdbusmessage.c b/gio/gdbusmessage.c
index 5a5fec880..0b77dc607 100644
--- a/gio/gdbusmessage.c
+++ b/gio/gdbusmessage.c
@@ -2852,7 +2852,7 @@ append_value_to_blob (GVariant            *value,
               const gchar *signature;
               child = g_variant_get_child_value (value, 0);
               signature = g_variant_get_type_string (child);
-              g_memory_buffer_put_byte (mbuf, strlen (signature));
+              g_memory_buffer_put_byte (mbuf, (guint8) strlen (signature));  /* signature is already validated to be this short */
               g_memory_buffer_put_string (mbuf, signature);
               g_memory_buffer_put_byte (mbuf, '\0');
               if (!append_value_to_blob (child,
diff --git a/gio/gdbusutils.c b/gio/gdbusutils.c
index a76e9ac1a..70825a557 100644
--- a/gio/gdbusutils.c
+++ b/gio/gdbusutils.c
@@ -113,7 +113,7 @@ is_valid_name (const gchar *start,
 gboolean
 g_dbus_is_name (const gchar *string)
 {
-  guint len;
+  size_t len;
   gboolean ret;
   const gchar *s;
 
diff --git a/gio/gdummyfile.c b/gio/gdummyfile.c
index 4ec352c6e..230977668 100644
--- a/gio/gdummyfile.c
+++ b/gio/gdummyfile.c
@@ -239,7 +239,7 @@ static const char *
 match_prefix (const char *path, 
               const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)
diff --git a/gio/gfilenamecompleter.c b/gio/gfilenamecompleter.c
index aca42498a..295ade05b 100644
--- a/gio/gfilenamecompleter.c
+++ b/gio/gfilenamecompleter.c
@@ -345,7 +345,7 @@ init_completion (GFilenameCompleter *completer,
   GFile *file, *parent;
   char *basename;
   char *t;
-  int len;
+  size_t len;
 
   *basename_out = NULL;
   
diff --git a/gio/gio-tool-mount.c b/gio/gio-tool-mount.c
index 13a78f7ca..5a35c1b36 100644
--- a/gio/gio-tool-mount.c
+++ b/gio/gio-tool-mount.c
@@ -89,7 +89,7 @@ prompt_for (const char *prompt, const char *default_value, gboolean echo)
   gboolean restore_flags;
 #endif
   char data[256];
-  int len;
+  size_t len;
 
   if (default_value && *default_value != 0)
     g_print ("%s [%s]: ", prompt, default_value);
diff --git a/gio/gio-tool-set.c b/gio/gio-tool-set.c
index 02622ba9e..324ee84de 100644
--- a/gio/gio-tool-set.c
+++ b/gio/gio-tool-set.c
@@ -42,10 +42,10 @@ static const GOptionEntry entries[] = {
 static char *
 hex_unescape (const char *str)
 {
-  int i;
+  size_t i;
   char *unescaped_str, *p;
   unsigned char c;
-  int len;
+  size_t len;
 
   len = strlen (str);
   unescaped_str = g_malloc (len + 1);
diff --git a/gio/glib-compile-schemas.c b/gio/glib-compile-schemas.c
index 04ef40457..54b980b0c 100644
--- a/gio/glib-compile-schemas.c
+++ b/gio/glib-compile-schemas.c
@@ -680,7 +680,7 @@ key_state_serialise (KeyState *state)
 
               if (state->l10n_context)
                 {
-                  gint len;
+                  size_t len;
 
                   /* Contextified messages are supported by prepending
                    * the context, followed by '\004' to the start of the
diff --git a/gio/glocalfile.c b/gio/glocalfile.c
index ceb888ad8..69dd60f81 100644
--- a/gio/glocalfile.c
+++ b/gio/glocalfile.c
@@ -479,7 +479,7 @@ static const char *
 match_prefix (const char *path, 
               const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)
diff --git a/gio/gresource-tool.c b/gio/gresource-tool.c
index 44b1f3f02..b6b51e763 100644
--- a/gio/gresource-tool.c
+++ b/gio/gresource-tool.c
@@ -83,7 +83,7 @@ list_resource (GResource   *resource,
   gint i;
   gchar *child;
   GError *error = NULL;
-  gint len;
+  size_t len;
 
   children = g_resource_enumerate_children (resource, path, 0, &error);
   if (error)
diff --git a/gio/gresource.c b/gio/gresource.c
index d19adf312..9454db3bf 100644
--- a/gio/gresource.c
+++ b/gio/gresource.c
@@ -352,7 +352,7 @@ g_resource_find_overlay (const gchar    *path,
   /* This is a null-terminated array of replacement strings (with '=' inside) */
   static const gchar * const *overlay_dirs;
   gboolean res = FALSE;
-  gint path_len = -1;
+  size_t path_len = 0;
   gint i;
 
   /* We try to be very fast in case there are no overlays.  Otherwise,
@@ -449,9 +449,9 @@ g_resource_find_overlay (const gchar    *path,
   for (i = 0; overlay_dirs[i]; i++)
     {
       const gchar *src;
-      gint src_len;
+      size_t src_len;
       const gchar *dst;
-      gint dst_len;
+      size_t dst_len;
       gchar *candidate;
 
       {
@@ -466,7 +466,7 @@ g_resource_find_overlay (const gchar    *path,
         /* hold off on dst_len because we will probably fail the checks below */
       }
 
-      if (path_len == -1)
+      if (i == 0)
         path_len = strlen (path);
 
       /* The entire path is too short to match the source */
diff --git a/gio/gresourcefile.c b/gio/gresourcefile.c
index 1621839cf..2fe37fdcc 100644
--- a/gio/gresourcefile.c
+++ b/gio/gresourcefile.c
@@ -354,7 +354,7 @@ static const char *
 match_prefix (const char *path,
 	      const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)
diff --git a/gio/gsocks5proxy.c b/gio/gsocks5proxy.c
index 71ac107da..42623391c 100644
--- a/gio/gsocks5proxy.c
+++ b/gio/gsocks5proxy.c
@@ -114,10 +114,10 @@ g_socks5_proxy_init (GSocks5Proxy *proxy)
  * +----+----------+----------+
  */
 #define SOCKS5_NEGO_MSG_LEN	  4
-static gint
+static size_t
 set_nego_msg (guint8 *msg, gboolean has_auth)
 {
-  gint len = 3;
+  size_t len = 3;
 
   msg[0] = SOCKS5_VERSION;
   msg[1] = 0x01; /* number of methods supported */
@@ -200,15 +200,20 @@ parse_nego_reply (const guint8 *data,
 }
 
 #define SOCKS5_AUTH_MSG_LEN       515
-static gint
-set_auth_msg (guint8	  *msg,
-	      const gchar *username,
-	      const gchar *password,
-	      GError **error)
+static gboolean
+set_auth_msg (guint8       *msg,
+              const gchar  *username,
+              const gchar  *password,
+              size_t       *out_len,
+              GError      **error)
 {
-  gint len = 0;
-  gint ulen = 0; /* username length */
-  gint plen = 0; /* Password length */
+  size_t len = 0;
+  size_t ulen = 0; /* username length */
+  size_t plen = 0; /* Password length */
+
+  /* Clear output first */
+  if (out_len != NULL)
+    *out_len = 0;
 
   if (username)
     ulen = strlen (username);
@@ -221,7 +226,7 @@ set_auth_msg (guint8	  *msg,
       g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 			   _("Username or password is too long for SOCKSv5 "
 			     "protocol."));
-      return -1;
+      return FALSE;
     }
 
   msg[len++] = SOCKS5_AUTH_VERSION;
@@ -238,7 +243,10 @@ set_auth_msg (guint8	  *msg,
 
   len += plen;
 
-  return len;
+  if (out_len != NULL)
+    *out_len = len;
+
+  return TRUE;
 }
 
 
@@ -266,13 +274,18 @@ check_auth_status (const guint8 *data, GError **error)
  * longer then 256 bytes.
  */
 #define SOCKS5_CONN_MSG_LEN	  262
-static gint
+static gboolean
 set_connect_msg (guint8       *msg,
-		 const gchar *hostname,
-		 guint16      port,
-		 GError     **error)
+                 const gchar  *hostname,
+                 guint16       port,
+                 size_t       *out_len,
+                 GError      **error)
 {
-  guint len = 0;
+  size_t len = 0;
+
+  /* Clear output first */
+  if (out_len != NULL)
+    *out_len = 0;
 
   msg[len++] = SOCKS5_VERSION;
   msg[len++] = SOCKS5_CMD_CONNECT;
@@ -301,7 +314,7 @@ set_connect_msg (guint8       *msg,
 	  g_set_error (error, G_IO_ERROR, G_IO_ERROR_PROXY_FAILED,
 		       _("Hostname “%s” is too long for SOCKSv5 protocol"),
 		       hostname);
-	  return -1;
+	  return FALSE;
 	}
 
       msg[len++] = SOCKS5_ATYP_DOMAINNAME;
@@ -316,7 +329,10 @@ set_connect_msg (guint8       *msg,
       len += 2;
     }
 
-  return len;
+  if (out_len != NULL)
+    *out_len = len;
+
+  return TRUE;
 }
 
 /*
@@ -447,7 +463,7 @@ g_socks5_proxy_connect (GProxy            *proxy,
   /* Send SOCKS5 handshake */
     {
       guint8 msg[SOCKS5_NEGO_MSG_LEN];
-      gint len;
+      size_t len;
 
       len = set_nego_msg (msg, has_auth);
 
@@ -471,12 +487,10 @@ g_socks5_proxy_connect (GProxy            *proxy,
       if (must_auth)
 	{
 	  guint8 msg[SOCKS5_AUTH_MSG_LEN];
-	  gint len;
+	  size_t len;
 
-	  len = set_auth_msg (msg, username, password, error);
-
-	  if (len < 0)
-	    goto error;
+	  if (!set_auth_msg (msg, username, password, &len, error))
+            goto error;
 	  
 	  if (!g_output_stream_write_all (out, msg, len, NULL,
 					  cancellable, error))
@@ -494,12 +508,10 @@ g_socks5_proxy_connect (GProxy            *proxy,
   /* Send SOCKS5 connection request */
     {
       guint8 msg[SOCKS5_CONN_MSG_LEN];
-      gint len;
+      size_t len;
       
-      len = set_connect_msg (msg, hostname, port, error);
-
-      if (len < 0)
-	goto error;
+      if (!set_connect_msg (msg, hostname, port, &len, error))
+        goto error;
 
       if (!g_output_stream_write_all (out, msg, len, NULL,
 				      cancellable, error))
@@ -561,8 +573,8 @@ typedef struct
   gchar *username;
   gchar *password;
   guint8 *buffer;
-  gssize length;
-  gssize offset;
+  size_t length;
+  size_t offset;
 } ConnectAsyncData;
 
 static void nego_msg_write_cb	      (GObject          *source,
@@ -751,13 +763,13 @@ nego_reply_read_cb (GObject      *source,
 	  g_free (data->buffer);
 
 	  data->buffer = g_malloc0 (SOCKS5_AUTH_MSG_LEN);
-	  data->length = set_auth_msg (data->buffer,
-				       data->username,
-				       data->password,
-				       &error);
-	  data->offset = 0;
+          data->offset = 0;
 
-	  if (data->length < 0)
+          if (!set_auth_msg (data->buffer,
+                             data->username,
+                             data->password,
+                             &data->length,
+                             &error))
 	    {
 	      g_task_return_error (task, error);
 	      g_object_unref (task);
@@ -873,13 +885,13 @@ send_connect_msg (GTask *task)
   g_free (data->buffer);
 
   data->buffer = g_malloc0 (SOCKS5_CONN_MSG_LEN);
-  data->length = set_connect_msg (data->buffer,
-				  data->hostname,
-				  data->port,
-				  &error);
   data->offset = 0;
-  
-  if (data->length < 0)
+
+  if (!set_connect_msg (data->buffer,
+                        data->hostname,
+                        data->port,
+                        &data->length,
+                        &error))
     {
       g_task_return_error (task, error);
       g_object_unref (task);
diff --git a/gio/gunixsocketaddress.c b/gio/gunixsocketaddress.c
index 3d1a26e1e..0ba499aac 100644
--- a/gio/gunixsocketaddress.c
+++ b/gio/gunixsocketaddress.c
@@ -472,15 +472,21 @@ g_unix_socket_address_new_with_type (const gchar            *path,
 {
   GSocketAddress *address;
   GByteArray *array;
+  size_t path_len_unsigned;
 
   if (type == G_UNIX_SOCKET_ADDRESS_ANONYMOUS)
-    path_len = 0;
-  else if (path_len == -1)
-    path_len = strlen (path);
+    path_len_unsigned = 0;
+  else if (path_len < 0)
+    path_len_unsigned = strlen (path);
+  else
+    path_len_unsigned = (size_t) path_len;
 
-  array = g_byte_array_sized_new (path_len);
+  /* The code below can’t handle anything longer. */
+  g_return_val_if_fail (path_len_unsigned <= G_MAXUINT, NULL);
 
-  g_byte_array_append (array, (guint8 *)path, path_len);
+  array = g_byte_array_sized_new (path_len_unsigned);
+
+  g_byte_array_append (array, (guint8 *)path, path_len_unsigned);
 
   address = g_object_new (G_TYPE_UNIX_SOCKET_ADDRESS,
 			  "path-as-array", array,
diff --git a/gio/tests/data-output-stream.c b/gio/tests/data-output-stream.c
index 0b324794d..1f52782a1 100644
--- a/gio/tests/data-output-stream.c
+++ b/gio/tests/data-output-stream.c
@@ -63,7 +63,7 @@ test_read_lines (GDataStreamNewlineType newline_type)
   GError *error = NULL;
   gpointer data;
   char *lines;
-  int size;
+  size_t size;
   int i;
 
 #define TEST_STRING	"some_text"
@@ -99,7 +99,7 @@ test_read_lines (GDataStreamNewlineType newline_type)
   
   /*  compare data */
   size = strlen (data);
-  g_assert_cmpint (size, <, MAX_LINES_BUFF);
+  g_assert_cmpuint (size, <, MAX_LINES_BUFF);
   g_assert_cmpstr ((char*)data, ==, lines);
   
   g_object_unref (base_stream);
diff --git a/gio/tests/task.c b/gio/tests/task.c
index a7f23125c..c9ae702a2 100644
--- a/gio/tests/task.c
+++ b/gio/tests/task.c
@@ -1470,7 +1470,7 @@ test_run_in_thread_overflow (void)
   GCancellable *cancellable;
   GTask *task;
   gchar buf[NUM_OVERFLOW_TASKS + 1];
-  gint i;
+  size_t i;
 
   /* Queue way too many tasks and then sleep for a bit. The first 10
    * tasks will be dispatched to threads and will then block on
@@ -1516,13 +1516,13 @@ test_run_in_thread_overflow (void)
    * plausibly get (and we hope that if gtask is actually broken then
    * it will exceed those limits).
    */
-  g_assert_cmpint (i, >=, 10);
+  g_assert_cmpuint (i, >=, 10);
   if (g_test_slow ())
-    g_assert_cmpint (i, <, 50);
+    g_assert_cmpuint (i, <, 50);
   else
-    g_assert_cmpint (i, <, 20);
+    g_assert_cmpuint (i, <, 20);
 
-  g_assert_cmpint (i + strspn (buf + i, "X"), ==, NUM_OVERFLOW_TASKS);
+  g_assert_cmpuint (i + strspn (buf + i, "X"), ==, NUM_OVERFLOW_TASKS);
 }
 
 /* test_return_on_cancel */
diff --git a/gio/win32/gwin32fsmonitorutils.c b/gio/win32/gwin32fsmonitorutils.c
index dd945dc87..d06dc458a 100644
--- a/gio/win32/gwin32fsmonitorutils.c
+++ b/gio/win32/gwin32fsmonitorutils.c
@@ -160,8 +160,8 @@ g_win32_fs_monitor_callback (DWORD        error,
 
           if (monitor->isfile)
             {
-              gint long_filename_length = wcslen (monitor->wfilename_long);
-              gint short_filename_length = wcslen (monitor->wfilename_short);
+              size_t long_filename_length = wcslen (monitor->wfilename_long);
+              size_t short_filename_length = wcslen (monitor->wfilename_short);
               enum GWin32FileMonitorFileAlias alias_state;
 
               /* If monitoring a file, check that the changed file
diff --git a/gio/win32/gwinhttpfile.c b/gio/win32/gwinhttpfile.c
index 605c28460..2e519b8f5 100644
--- a/gio/win32/gwinhttpfile.c
+++ b/gio/win32/gwinhttpfile.c
@@ -318,7 +318,7 @@ static const char *
 match_prefix (const char *path,
               const char *prefix)
 {
-  int prefix_len;
+  size_t prefix_len;
 
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)
diff --git a/girepository/gibaseinfo.c b/girepository/gibaseinfo.c
index ccc5aed37..d85106f65 100644
--- a/girepository/gibaseinfo.c
+++ b/girepository/gibaseinfo.c
@@ -223,12 +223,14 @@ gi_base_info_type_register_static (const char     *type_name,
 {
   GTypeInfo info;
 
+  g_assert (instance_size <= G_MAXUINT16);
+
   info.class_size = sizeof (GIBaseInfoClass);
   info.base_init = NULL;
   info.base_finalize = NULL;
   info.class_init = class_init;
   info.class_finalize = NULL;
-  info.instance_size = instance_size;
+  info.instance_size = (guint16) instance_size;
   info.n_preallocs = 0;
   info.instance_init = NULL;
   info.value_table = NULL;
diff --git a/girepository/gicallableinfo.c b/girepository/gicallableinfo.c
index 49430e9a8..23d31f1a4 100644
--- a/girepository/gicallableinfo.c
+++ b/girepository/gicallableinfo.c
@@ -651,7 +651,7 @@ gi_callable_info_invoke (GICallableInfo    *info,
   GITypeInfo *rinfo;
   GITypeTag rtag;
   GIArgInfo *ainfo;
-  size_t n_args, n_invoke_args, in_pos, out_pos, i;
+  unsigned int n_args, n_invoke_args, in_pos, out_pos, i;
   void **args;
   gboolean success = FALSE;
   GError *local_error = NULL;
diff --git a/girepository/gifieldinfo.c b/girepository/gifieldinfo.c
index 819ccf72b..24b2a5e6d 100644
--- a/girepository/gifieldinfo.c
+++ b/girepository/gifieldinfo.c
@@ -190,7 +190,7 @@ gi_field_info_get_field (GIFieldInfo *field_info,
                          void        *mem,
                          GIArgument  *value)
 {
-  int offset;
+  size_t offset;
   GITypeInfo *type_info;
   gboolean result = FALSE;
 
@@ -385,7 +385,7 @@ gi_field_info_set_field (GIFieldInfo      *field_info,
                          void             *mem,
                          const GIArgument *value)
 {
-  int offset;
+  size_t offset;
   GITypeInfo *type_info;
   gboolean result = FALSE;
 
diff --git a/girepository/girnode.c b/girepository/girnode.c
index efc022d72..b3ea89323 100644
--- a/girepository/girnode.c
+++ b/girepository/girnode.c
@@ -571,7 +571,7 @@ gi_ir_node_get_size (GIIrNode *node)
 
   g_assert (size <= G_MAXUINT32);
 
-  return size;
+  return (guint32) size;
 }
 
 static void
diff --git a/girepository/girwriter.c b/girepository/girwriter.c
index a0307a29d..d0b5d0803 100644
--- a/girepository/girwriter.c
+++ b/girepository/girwriter.c
@@ -1338,7 +1338,8 @@ gi_ir_writer_write (GIRepository *repository,
                     gboolean    show_all)
 {
   FILE *ofile;
-  size_t i, j;
+  size_t i;
+  unsigned int j;
   char **dependencies;
   Xml *xml;
 
diff --git a/glib/gbase64.c b/glib/gbase64.c
index 043593b05..2ea4a4ef4 100644
--- a/glib/gbase64.c
+++ b/glib/gbase64.c
@@ -424,7 +424,8 @@ guchar *
 g_base64_decode_inplace (gchar *text,
                          gsize *out_len)
 {
-  gint input_length, state = 0;
+  gint state = 0;
+  size_t input_length;
   guint save = 0;
 
   g_return_val_if_fail (text != NULL, NULL);
diff --git a/glib/gdate.c b/glib/gdate.c
index c509bd303..c0d486c9d 100644
--- a/glib/gdate.c
+++ b/glib/gdate.c
@@ -2258,6 +2258,7 @@ win32_strftime_helper (const GDate     *d,
   gchar *convbuf;
   glong convlen = 0;
   gsize retval;
+  size_t format_len = strlen (format);
 
   systemtime.wYear = tm->tm_year + 1900;
   systemtime.wMonth = tm->tm_mon + 1;
@@ -2269,7 +2270,8 @@ win32_strftime_helper (const GDate     *d,
   systemtime.wMilliseconds = 0;
   
   lcid = GetThreadLocale ();
-  result = g_array_sized_new (FALSE, FALSE, sizeof (wchar_t), MAX (128, strlen (format) * 2));
+  result = g_array_sized_new (FALSE, FALSE, sizeof (wchar_t),
+                              (format_len <= 64) ? (guint) format_len * 2 : 128);
 
   p = format;
   while (*p)
diff --git a/glib/gdatetime.c b/glib/gdatetime.c
index b5372d834..702a77c51 100644
--- a/glib/gdatetime.c
+++ b/glib/gdatetime.c
@@ -3268,7 +3268,7 @@ g_date_time_format_utf8 (GDateTime   *datetime,
 			 GString     *outstr,
 			 gboolean     locale_is_utf8)
 {
-  guint     len;
+  size_t len;
   guint     colons;
   gunichar  c;
   gboolean  alt_digits = FALSE;
diff --git a/glib/genviron.c b/glib/genviron.c
index b72871b95..2b0136006 100644
--- a/glib/genviron.c
+++ b/glib/genviron.c
@@ -647,7 +647,7 @@ g_get_environ (void)
 {
   gunichar2 *strings;
   gchar **result;
-  gint i, n;
+  size_t i, n;
 
   strings = GetEnvironmentStringsW ();
   for (n = 0, i = 0; strings[n]; i++)
diff --git a/glib/gfileutils.c b/glib/gfileutils.c
index 2801777e4..f40400ca5 100644
--- a/glib/gfileutils.c
+++ b/glib/gfileutils.c
@@ -373,7 +373,7 @@ g_file_test (const gchar *filename,
     {
       const gchar *lastdot = strrchr (filename, '.');
       const gchar *pathext = NULL, *p;
-      int extlen;
+      size_t extlen;
 
       if (lastdot == NULL)
         break;
@@ -401,7 +401,7 @@ g_file_test (const gchar *filename,
 	  const gchar *q = strchr (p, ';');
 	  if (q == NULL)
 	    q = p + strlen (p);
-	  if (extlen == q - p &&
+	  if (extlen == (size_t) (q - p) &&
 	      memcmp (lastdot, p, extlen) == 0)
 	    {
 	      g_free ((gchar *) pathext);
diff --git a/glib/gmessages.c b/glib/gmessages.c
index f325a9196..2ce651a71 100644
--- a/glib/gmessages.c
+++ b/glib/gmessages.c
@@ -1420,9 +1420,9 @@ win32_is_pipe_tty (int fd)
   gboolean result = FALSE;
   HANDLE h_fd;
   FILE_NAME_INFO *info = NULL;
-  gint info_size = sizeof (FILE_NAME_INFO) + sizeof (WCHAR) * MAX_PATH;
+  size_t info_size = sizeof (FILE_NAME_INFO) + sizeof (WCHAR) * MAX_PATH;
   wchar_t *name = NULL;
-  gint length;
+  size_t length;
 
   h_fd = (HANDLE) _get_osfhandle (fd);
 
diff --git a/glib/goption.c b/glib/goption.c
index 530e0cdba..785b151f0 100644
--- a/glib/goption.c
+++ b/glib/goption.c
@@ -1461,7 +1461,7 @@ parse_long_option (GOptionContext *context,
         }
       else
         {
-          gint len = strlen (group->entries[j].long_name);
+          size_t len = strlen (group->entries[j].long_name);
 
           if (strncmp (arg, group->entries[j].long_name, len) == 0 &&
               (arg[len] == '=' || arg[len] == 0))
diff --git a/glib/gpattern.c b/glib/gpattern.c
index bf61da36f..f77e69b6b 100644
--- a/glib/gpattern.c
+++ b/glib/gpattern.c
@@ -65,9 +65,9 @@ typedef enum
 struct _GPatternSpec
 {
   GMatchType match_type;
-  guint      pattern_length;
-  guint      min_length;
-  guint      max_length;
+  size_t     pattern_length;
+  size_t     min_length;
+  size_t     max_length;
   gchar     *pattern;
 };
 
diff --git a/glib/gstrfuncs.c b/glib/gstrfuncs.c
index 9af21a953..3688bea49 100644
--- a/glib/gstrfuncs.c
+++ b/glib/gstrfuncs.c
@@ -930,7 +930,7 @@ g_ascii_formatd (gchar       *buffer,
   const char *decimal_point;
   gsize decimal_point_len;
   gchar *p;
-  int rest_len;
+  size_t rest_len;
   gchar format_char;
 
   g_return_val_if_fail (buffer != NULL, NULL);
diff --git a/glib/gstring.c b/glib/gstring.c
index 463bfeccc..bdd068344 100644
--- a/glib/gstring.c
+++ b/glib/gstring.c
@@ -134,7 +134,7 @@ g_string_new (const gchar *init)
     string = g_string_sized_new (2);
   else
     {
-      gint len;
+      size_t len;
 
       len = strlen (init);
       string = g_string_sized_new (len + 2);
diff --git a/glib/gtestutils.c b/glib/gtestutils.c
index 5c5f9051f..253cfa7b3 100644
--- a/glib/gtestutils.c
+++ b/glib/gtestutils.c
@@ -3035,7 +3035,7 @@ static gboolean
 path_has_prefix (const char *path,
                  const char *prefix)
 {
-  int prefix_len = strlen (prefix);
+  size_t prefix_len = strlen (prefix);
 
   return (strncmp (path, prefix, prefix_len) == 0 &&
           (path[prefix_len] == '\0' ||
diff --git a/glib/gtranslit.c b/glib/gtranslit.c
index c264241cc..85ffb1326 100644
--- a/glib/gtranslit.c
+++ b/glib/gtranslit.c
@@ -187,11 +187,11 @@ lookup_item_id_for_locale (const gchar *locale)
 {
   gchar key[MAX_LOCALE_NAME + 1];
   const gchar *language;
-  guint language_len;
+  size_t language_len;
   const gchar *territory = NULL;
-  guint territory_len = 0;
+  size_t territory_len = 0;
   const gchar *modifier = NULL;
-  guint modifier_len = 0;
+  size_t modifier_len = 0;
   const gchar *next_char;
   guint id;
 
diff --git a/glib/guniprop.c b/glib/guniprop.c
index 61acad6e6..e147829e2 100644
--- a/glib/guniprop.c
+++ b/glib/guniprop.c
@@ -805,7 +805,7 @@ output_special_case (gchar *out_buffer,
 		     int    which)
 {
   const gchar *p = special_case_table + offset;
-  gint len;
+  size_t len;
 
   if (type != G_UNICODE_TITLECASE_LETTER)
     p = g_utf8_next_char (p);
diff --git a/glib/gutf8.c b/glib/gutf8.c
index 5a875ce26..dd9966df5 100644
--- a/glib/gutf8.c
+++ b/glib/gutf8.c
@@ -1250,7 +1250,7 @@ g_utf16_to_ucs4 (const gunichar2  *str,
   const gunichar2 *in;
   gchar *out;
   gchar *result = NULL;
-  gint n_bytes;
+  size_t n_bytes;
   gunichar high_surrogate;
 
   g_return_val_if_fail (str != NULL, NULL);
diff --git a/glib/gutils.c b/glib/gutils.c
index 5eaa63845..057e2bcd7 100644
--- a/glib/gutils.c
+++ b/glib/gutils.c
@@ -196,7 +196,7 @@ g_find_program_in_path (const gchar *program)
       strchr (last_dot, '\\') != NULL ||
       strchr (last_dot, '/') != NULL)
     {
-      const gint program_length = strlen (program);
+      const size_t program_length = strlen (program);
       gchar *pathext = g_build_path (";",
 				     ".exe;.cmd;.bat;.com",
 				     g_getenv ("PATHEXT"),
diff --git a/glib/gvariant-parser.c b/glib/gvariant-parser.c
index 243a34f57..8bd16766c 100644
--- a/glib/gvariant-parser.c
+++ b/glib/gvariant-parser.c
@@ -327,10 +327,10 @@ static gboolean
 token_stream_peek_string (TokenStream *stream,
                           const gchar *token)
 {
-  gint length = strlen (token);
+  size_t length = strlen (token);
 
   return token_stream_prepare (stream) &&
-         stream->stream - stream->this == length &&
+         (size_t) (stream->stream - stream->this) == length &&
          memcmp (stream->this, token, length) == 0;
 }
 
diff --git a/glib/tests/array-test.c b/glib/tests/array-test.c
index 70f56e8a1..df9d15bdc 100644
--- a/glib/tests/array-test.c
+++ b/glib/tests/array-test.c
@@ -133,7 +133,7 @@ array_new_zero_terminated (void)
   garray = g_array_new (TRUE, FALSE, sizeof (gchar));
   g_assert_cmpuint (garray->len, ==, 0);
 
-  g_array_append_vals (garray, "hello", strlen ("hello"));
+  g_array_append_vals (garray, "hello", (guint) strlen ("hello"));
   g_assert_cmpuint (garray->len, ==, 5);
   g_assert_cmpstr (garray->data, ==, "hello");
 
diff --git a/glib/tests/gvariant.c b/glib/tests/gvariant.c
index c24cd2f3e..27586be71 100644
--- a/glib/tests/gvariant.c
+++ b/glib/tests/gvariant.c
@@ -313,7 +313,7 @@ invalid_mutation (const gchar *type_string)
 
   /* else, perform a random mutation at a random point */
   {
-    gint length, n;
+    size_t length, n;
     gchar *new;
     gchar p;
 
diff --git a/glib/tests/pattern.c b/glib/tests/pattern.c
index b590acb8a..414b86358 100644
--- a/glib/tests/pattern.c
+++ b/glib/tests/pattern.c
@@ -37,9 +37,9 @@ typedef enum
 struct _GPatternSpec
 {
   GMatchType match_type;
-  guint      pattern_length;
-  guint      min_length;
-  guint      max_length;
+  size_t     pattern_length;
+  size_t     min_length;
+  size_t     max_length;
   gchar     *pattern;
 };
 
@@ -50,7 +50,7 @@ struct _CompileTest
   const gchar *src;
   GMatchType match_type;
   gchar *pattern;
-  guint min;
+  size_t min;
 };
 
 static CompileTest compile_tests[] = {
@@ -80,8 +80,8 @@ test_compilation (gconstpointer d)
 
   g_assert_cmpint (spec->match_type, ==, test->match_type);
   g_assert_cmpstr (spec->pattern, ==, test->pattern);
-  g_assert_cmpint (spec->pattern_length, ==, strlen (spec->pattern));
-  g_assert_cmpint (spec->min_length, ==, test->min);
+  g_assert_cmpuint (spec->pattern_length, ==, strlen (spec->pattern));
+  g_assert_cmpuint (spec->min_length, ==, test->min);
 
   g_pattern_spec_free (spec);
 }
@@ -97,8 +97,8 @@ test_copy (gconstpointer d)
 
   g_assert_cmpint (p2->match_type, ==, test->match_type);
   g_assert_cmpstr (p2->pattern, ==, test->pattern);
-  g_assert_cmpint (p2->pattern_length, ==, strlen (p1->pattern));
-  g_assert_cmpint (p2->min_length, ==, test->min);
+  g_assert_cmpuint (p2->pattern_length, ==, strlen (p1->pattern));
+  g_assert_cmpuint (p2->min_length, ==, test->min);
 
   g_pattern_spec_free (p1);
   g_pattern_spec_free (p2);
@@ -186,7 +186,8 @@ test_match (gconstpointer d)
   r = g_utf8_strreverse (test->string, -1);
   g_assert_cmpint (g_pattern_spec_match (p, strlen (test->string), test->string, r), ==, test->match);
   G_GNUC_BEGIN_IGNORE_DEPRECATIONS
-  g_assert_cmpint (g_pattern_match (p, strlen (test->string), test->string, r), ==, test->match);
+  g_assert_cmpuint (strlen (test->string), <=, G_MAXUINT);
+  g_assert_cmpint (g_pattern_match (p, (guint) strlen (test->string), test->string, r), ==, test->match);
   G_GNUC_END_IGNORE_DEPRECATIONS
   g_free (r);
 
diff --git a/glib/tests/scannerapi.c b/glib/tests/scannerapi.c
index cee3956ea..715dd14d3 100644
--- a/glib/tests/scannerapi.c
+++ b/glib/tests/scannerapi.c
@@ -111,7 +111,7 @@ test_scanner_tokens (ScannerFixture *fix,
                      gconstpointer   test_data)
 {
   gchar buf[] = "(\t\n\r\\){}";
-  const gint buflen = strlen (buf);
+  const size_t buflen = strlen (buf);
   gchar tokbuf[] = "(\\){}";
   const gsize tokbuflen = strlen (tokbuf);
   gsize i;
diff --git a/glib/tests/spawn-test-win32-gui.c b/glib/tests/spawn-test-win32-gui.c
index 46353c8f3..a84fe83ff 100644
--- a/glib/tests/spawn-test-win32-gui.c
+++ b/glib/tests/spawn-test-win32-gui.c
@@ -36,7 +36,8 @@ WinMain (struct HINSTANCE__ *hInstance,
     {
       int infd = atoi (__argv[2]);
       int outfd = atoi (__argv[3]);
-      int k, n;
+      SSIZE_T k;
+      size_t n;
       char buf[100] = {0};
 
       if (infd < 0 || outfd < 0)
@@ -55,22 +56,28 @@ WinMain (struct HINSTANCE__ *hInstance,
 	  exit (1);
 	}
 
-      if ((k = read (infd, &n, sizeof (n))) != sizeof (n))
+      k = read (infd, &n, sizeof (n));
+      if (k < 0 || (size_t) k != sizeof (n))
 	{
-          fprintf (stderr, "spawn-test-win32-gui: Got only %d bytes, wanted %d\n",
-		   k, (int)sizeof (n));
+	  int errsv = errno;
+	  if (k < 0)
+            fprintf (stderr, "spawn-test-win32-gui: Read error: %s\n", strerror (errsv));
+	  else
+            fprintf (stderr, "spawn-test-win32-gui: Got only %zu bytes, wanted %zu\n",
+                     (size_t) k, sizeof (n));
 	  exit (1);
 	}
 
-      fprintf (stderr, "spawn-test-win32-gui: Parent says %d bytes to read\n", n);
+      fprintf (stderr, "spawn-test-win32-gui: Parent says %zu bytes to read\n", n);
 
-      if ((k = read (infd, buf, n)) != n)
+      k = read (infd, buf, n);
+      if (k < 0 || (size_t) k != n)
 	{
 	  int errsv = errno;
-	  if (k == -1)
+	  if (k < 0)
             fprintf (stderr, "spawn-test-win32-gui: Read error: %s\n", strerror (errsv));
 	  else
-            fprintf (stderr, "spawn-test-win32-gui: Got only %d bytes\n", k);
+            fprintf (stderr, "spawn-test-win32-gui: Got only %zu bytes\n", (size_t) k);
 	  exit (1);
 	}
 
diff --git a/glib/tests/spawn-test.c b/glib/tests/spawn-test.c
index fdc35e86f..779645a13 100644
--- a/glib/tests/spawn-test.c
+++ b/glib/tests/spawn-test.c
@@ -198,7 +198,7 @@ test_spawn_basics (void)
   gchar *output = NULL;
   gchar *erroutput = NULL;
 #ifdef G_OS_WIN32
-  int n;
+  size_t n;
   char buf[100];
   int pipedown[2], pipeup[2];
   gchar **argv = NULL;
diff --git a/glib/tests/tree.c b/glib/tests/tree.c
index 055a2c266..6e7fc0b5a 100644
--- a/glib/tests/tree.c
+++ b/glib/tests/tree.c
@@ -455,7 +455,7 @@ test_tree_insert (void)
 {
   GTree *tree;
   gchar *p;
-  gint i;
+  size_t i;
   gchar *scrambled;
 
   tree = g_tree_new (my_compare);
@@ -468,8 +468,8 @@ test_tree_insert (void)
   g_tree_unref (tree);
   tree = g_tree_new (my_compare);
 
-  for (i = strlen (chars) - 1; i >= 0; i--)
-    g_tree_insert (tree, &chars[i], &chars[i]);
+  for (i = strlen (chars); i > 0; i--)
+    g_tree_insert (tree, &chars[i - 1], &chars[i - 1]);
   p = chars;
   g_tree_foreach (tree, check_order, &p);
 
diff --git a/gmodule/gmodule-win32.c b/gmodule/gmodule-win32.c
index bea841271..5748bef0f 100644
--- a/gmodule/gmodule-win32.c
+++ b/gmodule/gmodule-win32.c
@@ -205,7 +205,7 @@ static gchar*
 _g_module_build_path (const gchar *directory,
 		      const gchar *module_name)
 {
-  gint k;
+  size_t k;
 
   k = strlen (module_name);
     
diff --git a/gobject/gobject-query.c b/gobject/gobject-query.c
index 76670320f..1cdff2ac6 100644
--- a/gobject/gobject-query.c
+++ b/gobject/gobject-query.c
@@ -47,7 +47,7 @@ show_nodes (GType        type,
 	    const gchar *indent)
 {
   GType   *children;
-  guint i;
+  size_t i;
   
   if (!type)
     return;
diff --git a/gobject/gtype.c b/gobject/gtype.c
index 8222fc493..b8e724092 100644
--- a/gobject/gtype.c
+++ b/gobject/gtype.c
@@ -1073,7 +1073,7 @@ type_data_make_W (TypeNode              *node,
 {
   TypeData *data;
   GTypeValueTable *vtable = NULL;
-  guint vtable_size = 0;
+  size_t vtable_size = 0;
   
   g_assert (node->data == NULL && info != NULL);